Meet Prospero: Robo-Farmer on Six Legs

THE GIST

- Instead of using tractors, farmers are turning to robots to plant and harvest crops.

- Swarm technology, game theory and infrared communications are being used to advance farming.

The future of farming lies not with genetically engineered seeds or super-fertilizers, instead it may come in new ways to plant, grow and harvest crops using robots instead of tractors.

That's according to an Iowa-based inventor who is basing his new bio-inspired autonomous robo-farmer on the swarming skills of insects, birds and fish.

By integrating swarm technology with game theory and robotic cooperation through infrared communications, David Dourhout has built several bug-like robo-farmers called Prospero that can plant individual seeds and remember where they are.

The small six-legged robots successfully planted an Iowa cornfield in a test run, and Dourhout hopes the next step will be to create more advanced robots that can weed, fertilize and harvest the crop.

"For last 1,000 years, the focus has been to increase the productivity of each farmer: building better implements, using horses, and the invention of McCormick's reapers and tractors," said Dourhout, a consulting entomologist and robot hobbyist. "But the real gains come in increasing productivity of the land itself."

Dourhout said that robots can make very precise decisions about where and when to plant seeds based on different kinds of soil type within the same field.

"With robots, you can make decision on foot by foot basis," he said. "It's customizable seed selection."

Rather than using a GPS device to lay a precise line of seeds on a field, the Prospero robots talk to each other as they crawl, staying within eight feet of each other. Eliminating a GPS unit helps keep the robots "brains" simple as well as lowering the cost of each unit.

"The most difficult thing was trying to figure out to know where the seeds had been planted," Dorhout said. "I didn't want an information dense system."

Dourhout thought about ants who emit a pheromone as a marking agent when they discover food. He designed Prospero to mark its planted seed with a spot of white spray paint that change the reflectivity of the ground. When other nearby robots pick up the change in reflectivity with a special sensor, they move on to another patch of soil.

Since a video of his robo-planters spread via YouTube, he's gotten interest from farmers in Brazil, Japan and Poland. The next step is scaling up the robots, and as with all autonomous devices, pushing battery power to extend their daily lifespan.

For farmers, there are some time during the year that planting needs to continue 24 hours a day in order to take advantage of temperature and soil conditions. Dourhout believes that he can build a larger "shepherd" robot that will run a hybrid gas-electric generator and recharge the batteries of the smaller robo-planters.

Given the increasing demands on U.S. farms to produce more food, and the small margins on which farmers operate, Dourhout and others expect to see more automation in the fields. Already, some firms have developed autonomous tractors to harvest wheat or corn, while a California group has developed an automated strawberry picker.

"If the robots could produce 20 percent more per acre," he said from Ames, Iowa, "that would be huge."

Big agri-business firms as well as small farmers are also feeling the push to grow more food without using more chemicals. Robots could play a role in that as well, according to Steve Young, a weed ecologist at the University of Nebraska-Lincoln.

"There's a lot of interest from industry in increasing productivity sustainably," Young said.

Young is working on designs for a robot that uses photo-sensors to detect the difference between a crop species and an invasive weed. That's one way of reducing the amount of herbicides which are usually sprayed across the entire field.

"You would have more than one tool at your disposal, Young said, "regardless of how you are growing your crop."